The manufacture of microcircuit devices by means of reactive-ion etching is now well established in the art. Two fairly recent patents which illustrate such processes are U.S. Pat. Nos. 4,026,742 and 4,057,460.
While reactive-ion etching has many advantages in the formation of microcircuits, it does have a disadvantage in the case of circuits based upon aluminum as the conductor. Aluminum which has been subjected to reactive-ion etching tends, upon the passage of time, to disintegrate. This disintegration causes open circuits and short circuits and is obviously a severe disadvantage.
The prior art teaches the treatment of aluminum containing alloys in an oxidizing atmosphere. U.S. Pat. No. 3,496,030 shows the treatment of an aluminum alloy in an atmosphere of helium containing steam. U.S. Pat. No. 3,660,173 shows the treatment of ferro alloys containing some aluminum in an oxidizing atmosphere at a temperature of 1000.degree. C. to 1400.degree. C.